my 1952 plunger B31 has what i understand is a M type gearbox the one with knurled screw cap to top up the oils and ajust the clutch i cant find the oil level plug i topped it up to the bottom lip of the top up hole but for the last two week oil has been leaking out of the gearbox output shaft

email (option): roger.beck@node6.com

Hi Roger..Both models in this period used the same gearbox..These ones don't have a level plug..just a drain plug and filler. The box should take a pint of oil approx. from empty after a rebuild..slightly less if it has only been drained...It should be noted that like the 'military' box early versions of this box had no oil seal, so leaked pretty much the same...If you have one of these the remedy is to change to the later main casing that has the seal fitted. By '52 the bike would have had the type with the seal fitted when new..Ian

email (option): ian@wright52.plus.com

This one pisses me off as well.
How did the folks at Armoury Road think we were to check the gearbox oil level, or was the idea to drain and refill instead?
I inevitably put too much in when I check the level and have to guess where it should be. Then I scatter the usual sawdust and newspapers around the garage floor to catch the mess that ensues! Moan…moan…moan

cheers
Pete

email (option): petercomley@web.de

It does no real harm if you slightly underfill it, say 7/8ths pint, as long as there is oil in there, or fit the sealed bearing with one seal picked out facing the inside, so that it is still lubricated by the gearboxes oil.

email (option): davmax@ntlworld.com

Hi Dave

I've already converted to the "half" sealed bearing on one bike and it has sorted it, I'm just putting off doing this bike, it seems so much trouble when a level indicator of some sort would have negated the need for a solution in the first place. Still moaning!
And one thing that really worries/scares the crap out of me is a siezed box - which would probably be on a downhill bend, knowing my luck.

Cheers
Pete

email (option): petercomley@web.de

ian you said to change the main casing with an oil seal in it can you go the sealed bearing route as in the m20 thanks ian for your help

email (option): roger.beck@node6.com